3/20/97

Hello all,

I have a PhD student from Brazil who is studying Catolaccus

grandis. He places a female on top of a beeswax cell which contains

boll weevil larva. The female deposits an egg on the larva and 2

weeks later, it matures and burrows its way out of the beeswax

creating a hole. He would like to study and measure these holes.

However, from past experience I know that beeswax melts when placed

in my Au/Pd sputter coater. Is there any way to coat the beeswax and

examine them with an SEM? Or should he try another route?

Thank you in advance,

Ginger Baker

EM Lab Manager

Dept. Anatomy, Pathology, and Pharmacology

250 Veterinary Medicine

Oklahoma State University

Stillwater, OK 74078

(405) 744-6765

FAX: (405) 744-5275

Email: lizard@okway.okstate.edu

Do you have cooling system on the sputter coater ? If your answer is

yes, let the beeswas sit on the cooling stage for 20 min then coat it

for 5-10 sec and pause for about 20 sec. Repeat it for 3-4 cycles. My

experience for fibric material the above tricks would work fine. Also you

may lower your sample far from the gold target to avoid heat.

Hope this will help.





Ming H. Chen, PhD

Medicine/Dentistry Electron Microscopy Unit

University Of Alberta.

Edmonton, Alberta, Canada

mingchen@gpu4.srv.ualberta.ca

Hi Ginger,

I guess the coater you used is a diode type of sputter coater. Heat is

generated during coating. In order to solve your problem, you should to

use a kind of "cooled sputter coater"-- planar magnetron sputter (PMS)

coater. A permanent magnet is positioned at the center of the cathode to

deflect the electrons away from the specimen.

Ya Chen



Integrated Microscopy Resource (IMR)--

an NIH Biomedical Research Resource TEL : 608-263-8481

University of Wisconsin-Madison FAX : 608-265-4076

1675 Observatory Drive #159 Email1:ychen14@facstaff.wisc.edu

Madison, WI 53706 Email2:chen@calshp.cals.wisc.edu

Reprosil is good, and so are any of the other polyvinyl siloxane impression

materials, available from any dental supplier. The resin can be Epon, or

302-1 from Epo-Tek or anything from the EM world.

Lesley Weston

lesley@unixg.ubc.ca

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